CAT3850 in endless reboot loop after upgrade attempt

[thomas.werner]

Hello.  I have a CAT3850-24S-E.  Before upgrade attempt I had IOS XE 16.12.05b.  I attempted upgrade using cat3k-universalk9.16.16.06.SPA.bin.  Following reload, system never returned.  I connected to serial console port.  System attempts boot and fails after about 6-8 minutes, and then reboots.  This process continues unless I power off switch.

I tried to factory reset.  Press and hold "mode" button during reboot.  I ended up with "switch:" prompt with a minimal command set.  I was able to format a USB drive with FAT32 and load a few "bin" files.  I am unable to copy these files from usbflash0: to flash:, as the ROMMON enforces readonly filesystem for flash:.  I tried changing flash: to rw with command "set_bs flash: rw".  The command did not throw any errors, however the filesystem remains "ro".

I also tried

"switch: emergency-install usbflash0:cat3k-universalk9.16.12.0bb.SPA.bin"

and

"switch: boot usbflash0:cat3k-universalk9.16.12.0bb.SPA.bin"

Both commands failed.  It appeared the tools were trying to write files to readonly filesystems.  Also, both commands deleted files from usbflash0: and I had to reload.

I hope someone on this forum has experienced similar problems and has a solution.  At this point the switch is now a "brick"!

[Reza Sharifi]

Hi,

Have a look at this link. You may want to try and format it with FAT16 and try again.

https://community.cisco.com/t5/switching/usb-not-recognized-in-3850/td-p/3096320

HTH

[thomas.werner]

Thank you.  The USB was formatted FAT32.  I reformatted USB and loaded binfiles.  I am now able to attempt to "emergency-install".  Now there is a new problem.  The "flash:" filesystem is no longer present.  I opened a new discussion topic for this.

[balaji.bandi]

Its not bricked, as for as i know.

connect console  ( capture all the logs)

1. Copy the right image  cat3k_caa-universalk9.16.12.05b.SPA.bin

2. make sure you use USB 4 or 8GB (not USB 3.0

3. Format FAT 16

4. Copy image

5. switch: 

switch: dir usbflash0:

you should see the file

6.  

boot usbflash0:cat3k_caa-universalk9.16.12.05b.SPA.bin

Let us know the out come (post the logs here)

[thomas.werner]

Thank you. Reformatting USB as FAT16 now allows CAT3850 ROMMON to write files on usbflash0.  I attempted install, now I have a new problem.  The "flash:" filesystem is not longer present.  I opened a new discussion topic.

[Leo Laohoo]

Console into the switch and reboot. 

We want to see what the switch is doing. 

When the switch boots into ROMMON, post the complete output to the following commands:

• dir flash:
• set

[thomas.werner]

Thank you for your response.  I reformatted USB as FAT16 and can now attempt "emergency-install".  The install fails due to missing "flash:" filesystem.  I opened a new discussion topic.  I included contents of "set" in new discussion before attempting "emergency-install".

[thomas.werner]

I replied to several posts here.  I got past the USB FAT16 issue.  Now I seem to have lost the flash: filesystem.  I posted a separate discussion topic with all of the logging, but somebody marked it a SPAM and it is gone!  I do not understand why it was marked spam...

[Reza Sharifi]

Hi Thomas,

Not sure why it was marked as SPAM. It appears that you have done everything you can with this switch. If you have a support contract on it, open a ticket with TAC and RMA the switch.

HTH

[thomas.werner]

Are you able to take off the SPAM tag? It is an important discussion item. It took me 45 minutes to manually type all of the log info as the system is not connected to any network. Thank you.

Tom Werner

[Reza Sharifi]

Tom,

Post the issue here and someone from the community support will respond to you.

https://community.cisco.com/t5/community-feedback-forum/bd-p/12122176-discussions-community-feedback

HTH